Lockboxes are typically used to a provide a secured storage area for a key or other access aid at a location close to a locked property accessible by the key. In this way, an authorized user can unlock the secured storage area, obtain the key and then use the key to unlock the locked property.
The locked property may be a home or other property that is locked while unattended by a traditional lock that requires a key. In other situations, the locked property may be a commercial or industrial site, or other type of property.
The lockbox is typically attached to a door handle or to another stationary object near the traditional lock. The lockbox is typically configured to require the user to demonstrate that he is authorized to obtain access to the locked property before the secured storage area is unlocked to allow the user to obtain the key. In a mechanical lockbox, the user might be required to enter a correct lock combination to access the secured storage area. In an electronic lockbox, the user might be required to communicate a credential to the lockbox (via a physical connection to the lockbox or via a wireless link to the lockbox) to access the secured storage area.
Conventional electronic lockboxes allow users to communicate their credentials wirelessly via the IrDa standard, i.e., by using infrared signals generated by the user's cellular telephone or personal digital assistant and directed toward the lockbox. In addition, information is typically communicated in the other direction, i.e., from the lockbox to the access device. Also, the lockbox and/or the access device may have other communications links, such as with a central authorization authority that issues credentials to users and collects information from lockboxes on access activity. Infrared communications require line of sight alignment, which is often inconvenient.
Other lockbox approaches use far-field RF communications, but these can lead to problems with interference, excessive power drain, regulatory concerns, difficulty in addressing only a specific desired lockbox among multiple lockboxes located in close proximity and higher component and maintenance costs.